GL450 Spark, then No Start
Thread Starter
Newbie
Joined: Apr 2019
Posts: 7
Likes: 1
From: Texas
2011 Mercedes GL450, 2006 E350, 2004 E320, 2017 C300
GL450 Spark, then No Start
2011 GL450. I had no communication with rear SAM, which disabled turn signals, wiper front cigarette lighter, lift gate and what-not. So I decided to remove the rear SAM, suspecting water might have got in there. Wound all windows down and didn’t remove battery cable while at it (lesson learned). While taking out the rear SAM the metal holder came in contact with a bolt on the fuse box in the trunk, which caused an electrical spark.
Rear SAM has some water damage to one attachment. Cleaned and put it back.
Since the spark, engine cranks but no start. Windows controls do not work (been covering the windows with tarp). OBD2 port does not work. I tested most of the fuses in the luggage compartment, in the engine compartment and the fuse box in the front passenger side and they are okay.
I’m at my wit’s end. Any help is appreciated.
Rear SAM has some water damage to one attachment. Cleaned and put it back.
Since the spark, engine cranks but no start. Windows controls do not work (been covering the windows with tarp). OBD2 port does not work. I tested most of the fuses in the luggage compartment, in the engine compartment and the fuse box in the front passenger side and they are okay.
I’m at my wit’s end. Any help is appreciated.
Last edited by kunleade; Sep 12, 2021 at 01:34 PM. Reason: To add GL450 to the title.
MBWorld Fanatic!
Joined: May 2015
Posts: 1,932
Likes: 291
From: Allentown, PA
'08 GL 320 CDI
I'm probably not the one to really dive deep into this to help, but I noticed you said you tested "most" of the fuses. I would at least start there and verify "all" the fuses and relays.
Other than that, I would assume that hooking up a STAR computer may lend some insight to what's going on. Or, at least point you in the direction of what system(s) aren't responding. Someone else can talk more about that, though.
Other than that, I would assume that hooking up a STAR computer may lend some insight to what's going on. Or, at least point you in the direction of what system(s) aren't responding. Someone else can talk more about that, though.
Out Of Control!!
Joined: Sep 2018
Posts: 14,679
Likes: 4,578
From: unbegrenzt
2017 GLE350 4MATIC
Because of the hot wire touching ground, you need to verify all fuses in the vehicle. Dig out the fuse diagram (paper), it's usually under the rear (second row) passenger seat tucked into one of the fuse boxes. Verify each and every fuse in the vehicle.
Super Member
Joined: Apr 2004
Posts: 625
Likes: 82
From: Germantown, MD
'07 GL450
In the mean time, for your windows, just disconnect the driver's side window controls and apply 12v directly to each contact on the harness to get them to raise
Use a Multi-meter to determine which lead is ground (test for continuity), then it's just a matter of connecting the negative to ground and the positive to each of the other leads, one-at-a-time. If I am not mistaken, switching polarity controls raising vs lowering.
Thread Starter
Newbie
Joined: Apr 2019
Posts: 7
Likes: 1
From: Texas
2011 Mercedes GL450, 2006 E350, 2004 E320, 2017 C300
I'm probably not the one to really dive deep into this to help, but I noticed you said you tested "most" of the fuses. I would at least start there and verify "all" the fuses and relays.
Other than that, I would assume that hooking up a STAR computer may lend some insight to what's going on. Or, at least point you in the direction of what system(s) aren't responding. Someone else can talk more about that, though.
Other than that, I would assume that hooking up a STAR computer may lend some insight to what's going on. Or, at least point you in the direction of what system(s) aren't responding. Someone else can talk more about that, though.
Thread Starter
Newbie
Joined: Apr 2019
Posts: 7
Likes: 1
From: Texas
2011 Mercedes GL450, 2006 E350, 2004 E320, 2017 C300
Thanks for the tip on raising the windows!
Would you know how I can move the front passenger seat forward so I can access the battery compartment under the seat?
Would you know how I can move the front passenger seat forward so I can access the battery compartment under the seat?
Thread Starter
Newbie
Joined: Apr 2019
Posts: 7
Likes: 1
From: Texas
2011 Mercedes GL450, 2006 E350, 2004 E320, 2017 C300
I'm probably not the one to really dive deep into this to help, but I noticed you said you tested "most" of the fuses. I would at least start there and verify "all" the fuses and relays.
Other than that, I would assume that hooking up a STAR computer may lend some insight to what's going on. Or, at least point you in the direction of what system(s) aren't responding. Someone else can talk more about that, though.
Other than that, I would assume that hooking up a STAR computer may lend some insight to what's going on. Or, at least point you in the direction of what system(s) aren't responding. Someone else can talk more about that, though.
Trending Topics
MBWorld Fanatic!
Joined: May 2015
Posts: 1,932
Likes: 291
From: Allentown, PA
'08 GL 320 CDI
You can unbolt the passenger seat - it's pretty simple and straight forward.
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Super Member
Joined: Apr 2004
Posts: 625
Likes: 82
From: Germantown, MD
'07 GL450
If the current position of the seat does not grant easy access, then you can disconnect the widest wiring harness under the respective seat and, as with the windows, apply 12v directly to the proper lead (sorry, I am not sure which lead that is). One note of caution: there are 3+ harnesses under each seat, the chrome harness is for SRS (seatbelts), once unplugged you would normally need to reset the SRS warning light via OBD (this may not be a problem at this point since your OBD does not seem to be functional).
Now, back to the SAM removal.
If the short occurred during removal of the SAM, there's a good chance your problem lies in the SAM itself. For reference, the following thread discusses the rear SAM wiring and has a .pdf with a wiring diagram:
https://mbworld.org/forums/gl-class-...am-wiring.html
Thread Starter
Newbie
Joined: Apr 2019
Posts: 7
Likes: 1
From: Texas
2011 Mercedes GL450, 2006 E350, 2004 E320, 2017 C300
Thanks! Will do just that.
Thread Starter
Newbie
Joined: Apr 2019
Posts: 7
Likes: 1
From: Texas
2011 Mercedes GL450, 2006 E350, 2004 E320, 2017 C300
2011 GL450. I had no communication with rear SAM, which disabled turn signals, wiper front cigarette lighter, lift gate and what-not. So I decided to remove the rear SAM, suspecting water might have got in there. Wound all windows down and didn’t remove battery cable while at it (lesson learned). While taking out the rear SAM the metal holder came in contact with a bolt on the fuse box in the trunk, which caused an electrical spark.
Rear SAM has some water damage to one attachment. Cleaned and put it back.
Since the spark, engine cranks but no start. Windows controls do not work (been covering the windows with tarp). OBD2 port does not work. I tested most of the fuses in the luggage compartment, in the engine compartment and the fuse box in the front passenger side and they are okay.
I’m at my wit’s end. Any help is appreciated.
Rear SAM has some water damage to one attachment. Cleaned and put it back.
Since the spark, engine cranks but no start. Windows controls do not work (been covering the windows with tarp). OBD2 port does not work. I tested most of the fuses in the luggage compartment, in the engine compartment and the fuse box in the front passenger side and they are okay.
I’m at my wit’s end. Any help is appreciated.
I took the car to the dealership. The pre-fuse in the battery compartment was blown from the spark, causing the car not to start. Rear SAM and the pre fuse box were replaced and everything works fine. Cost about $2500, most of it being labor charges.
I think water got onto the rear SAM board again: driver side reverse light stays on even when engine is off and the fuel gauge stopped working. May need to go to dealership again as the rear SAM is still under warranty.
